/*
 * Copyright (C) 2019 Adaptech s.r.o., Robert Pösel
 * Copyright (C) 2014 Robert Theis
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.googlecode.leptonica.android;

public class GrayQuant {
	static {
		System.loadLibrary("jpeg");
		System.loadLibrary("png");
		System.loadLibrary("leptonica");
	}

	/**
	 * Perform simple (pixelwise) binarization with fixed threshold
	 * <p>
	 * Notes:
	 * <ol>
	 * <li> If the source pixel is less than the threshold value, the dest will
	 * be 1; otherwise, it will be 0
	 * </ol>
	 *
	 * @param pixs   Source pix (4 or 8 bpp)
	 * @param thresh Threshold value
	 * @return a new Pix image, 1 bpp
	 */
	public static Pix pixThresholdToBinary(Pix pixs, int thresh) {
		if (pixs == null)
			throw new IllegalArgumentException("Source pix must be non-null");
		int depth = pixs.getDepth();
		if (depth != 4 && depth != 8)
			throw new IllegalArgumentException("Source pix depth must be 4 or 8 bpp");
		if (depth == 4 && thresh > 16)
			throw new IllegalArgumentException("4 bpp thresh not in {0-16}");
		if (depth == 8 && thresh > 256)
			throw new IllegalArgumentException("8 bpp thresh not in {0-256}");

		long nativePix = nativePixThresholdToBinary(pixs.getNativePix(),
				thresh);

		if (nativePix == 0)
			throw new RuntimeException("Failed to perform binarization");

		return new Pix(nativePix);
	}

	// ***************
	// * NATIVE CODE *
	// ***************

	private static native long nativePixThresholdToBinary(long nativePix, int thresh);
}
